In form ... Joe Root drives towards his 50 against the Invitational XI.

AAP: Dean Lewins

Joe Root continued the momentum England's batsmen are taking into the Ashes series starting next week in Brisbane.

Root (75) became the fourth member of the England top order to pass 50 in the tour match against the Cricket Australia Invitational XI in Sydney, with the baby-faced number six sharing in a sixth-wicket partnership with wicketkeeper Jonny Bairstow (48) of 106.

Bowling remains a concern for the tourists ahead of the Gabba, but the batting line-up picks itself, with the tourists notching up 418 in their first innings.

The top three and Ian Bell all have tons so far on tour, while Kevin Pietersen and Root have half-centuries under their belt.

With regular wicketkeeper Matt Prior in doubt for Brisbane with a calf strain, Bairstow may also come into selection calculations despite enduring an unhappy series with the bat against Australia in the winter.

There was a moment of concern for Root, when he was struck on the right hand by Josh Lalor when the Invitational quick took the second new ball.

Trainers came out to tend to Root, but the 23-year-old carried on batting and passed 50 with six fours.

Root was unlucky to be dropped as an opener, but early signs suggest he could be in for a fruitful summer at number six.